var app = new Vue({
    el: "#app",
    data: {
        arr: [
            "media/xiaomi.mp4",
            "media/xiaomi.mp4",
            "media/xiaomi.mp4",
            "media/xiaomi.mp4",
            "media/xiaomi.mp4"
        ],
        index: 0
    },
    methods: {
        one: function () { this.index = 0; },
        two: function () { this.index = 1; },
        three: function () { this.index = 2; },
        four: function () { this.index = 3; },
        five: function () { this.index = 4; }
    }
})